insulator

 
Pronunciation: /ˈɪnsjʊleɪtə/

noun

  • a substance which does not readily allow the passage of heat or sound: cotton is a poor insulator
  • a substance or device which does not readily conduct electricity: a series of electrodes separated by insulators
  • a block of glass, ceramic, or other insulating material enclosing a wire carrying an electric current where it crosses a support.